The present disclosure describes a catheter useful for treating a vessel of a subject. The catheter comprises an outer sheath that surrounds a multilumenal tubing. The catheter further comprises a slotted hypotube that at least partially surrounds the multilumenal tubing. A tube holder houses the multilumenal tubing, and the slotted hypotube is configured to slide within internal passages or channels within the tube holder, such that the hypotube slides relative to both the tube holder and the multilumenal tubing. The slotted hypotube combined with the tube holder provides advantages over existing catheters further described herein.